Bar codes have been used to identify objects for some time. These are linear sequence of black bars against a white (or light) background. To increase the amount of information encoded, two-dimensional codes in both an “x” and a “y” direction were developed. (e.g., U.S. Pat. No. 5,726,435, M. Hara, et al., “Optically readable two-dimensional code and method and apparatus for the same.”). In addition, for “linear bar codes, a “2nd dimension” could be added by varying the heights of the bars. For printable bar codes, color could also be used as an additional dimension.
All of these types of codes are readily counterfeited or copies, by ‘xeroxing’ and by generating the codes according to a decrypted or otherwise known methodology.
A more secure approach is to have actual three-dimensional codes (“x”, “y” and “z” directions) printed by the techniques of three-dimensional printing. This type of “3-dimensional” coding does not appear to have been exploited. In this “x-y-z” three dimensionality, color may also be added as a “4-th dimension”.
It should be noted that ‘light-field’ cameras have been developed which can capture a more complete depth of field than conventional cameras and which can show different focal planes of a scene upon demand. (e.g., U.S. Pat. No. 8,471,897, Rodriguez Ramos, et al, “Camera for the real-time acquisition of visual information fro three-dimensional scene”; U.S. Pat. No. 8,290,358, T. G. Giorgiev, “Method and apparatus for light imaging field;”, U.S. Pat. No. 8,531,783, Zalevsky et al., “Imaging method and system for imaging with extended depth of focus.”)
I Further one notes the development of “three-dimensional printing techniques which can be used to deposit, by printing, three-dimensional objects. For example, see U.S. Pat. No. 5,204,055, Sachs, et al., Three-dimensional printing techniques.